Aerogel belt signal transmission novel fireproof cable and preparation method thereof

Abstract

The application provides a new type of aerogel belt signal transmission fireproof cable and a preparation method thereof. The cable is constructed by a basalt fiber cloth-modified aerogel composite belt, a ceramicized silica gel belt and a spiral water channel to form a three-level synergistic fireproof system, and is matched with a signal line core structure of a steel wire reinforcing layer. The modified aerogel layer is compounded with expandable graphite micropowder at a specific ratio, the synergistic effect of the nanometer pore heat insulation of the aerogel, the high-temperature expansion hole sealing of the expandable graphite and the blocking of the ceramicized shell is utilized, and the heat insulation efficiency and the fire resistance time under high temperature are greatly improved. Meanwhile, the spiral water channel has the dual functions of daily water-proofing and moisture-proofing and fire disaster evaporation cooling, and the signal line steel wire reinforcing layer simultaneously realizes tensile strengthening and electromagnetic shielding, so that the cable has excellent fireproof and fire-resistant performance, mechanical tensile strength, water-proofing and moisture-proofing performance and stable signal transmission capacity, and can be stably applied to harsh working conditions such as high-rise buildings and subways, and has the advantages of controllable preparation process, stable performance and easy popularization and implementation.

Description

Technical Field

[0001] This application belongs to the field of wire and cable manufacturing technology, specifically relating to a novel fireproof cable for signal transmission using aerogel tape and its preparation method. Background Technology

[0002] As the core carrier of power and signal transmission, cables play a crucial role in the safe operation of special scenarios such as high-rise buildings, subway tunnels, and nuclear power plants. They not only need to ensure stable power transmission but also undertake signal transmission functions such as fire control, status monitoring, and emergency communication, directly determining the response capability of emergency systems and the level of protection for personnel escape and equipment safety under extreme conditions such as fires. However, currently available fire-resistant cables that combine power and signal transmission functions still have many performance shortcomings and deficiencies in practical applications that are difficult to balance.

[0003] In existing technologies, the first type of conventional fire-resistant cables mostly achieve basic fire resistance by adding flame retardants to the insulation layer or sheath and combining them with a mica tape fire-resistant layer. This approach is simple in structure and low in cost, and can meet the short-term fire protection requirements of ordinary buildings. However, it has significant drawbacks in extreme high-temperature fire scenarios. These cables generally have insufficient thermal insulation, allowing heat from flames to be rapidly transferred to the cable core. This can cause the insulation layer to melt and the conductor resistance to surge within a short time, leading to power outages and signal loss. They cannot meet the line integrity requirements of more than 90 minutes in scenarios such as nuclear power plants and subway tunnels. Furthermore, conventional flame-retardant materials easily produce toxic fumes and molten drips when burning, which can easily cause secondary disasters. The overall mechanical strength, tensile strength, and waterproof performance of these cables are also insufficient, making them unsuitable for complex laying environments with high humidity and external loads. In addition, in these cables, power lines and signal lines are only isolated by simple filling. Electromagnetic interference generated by power transmission can easily cause signal transmission distortion and increased bit error rate, failing to guarantee the stable transmission of high-precision signals.

[0004] To improve thermal insulation and fire resistance, the existing second-type solution introduces aerogel materials into the fireproof structure of cables, utilizing the nanoporous thermal insulation properties of aerogel to enhance fire resistance. However, this type of solution has insurmountable application shortcomings: On the one hand, conventional glass fiber-based pure silica aerogel tape has poor mechanical properties, and the aerogel powder is prone to detachment and pulverization during cable bending and laying, and the nanoporous structure is prone to collapse, resulting in a significant decrease in thermal insulation performance and insufficient long-term service stability. On the other hand, the pore structure of pure silica aerogel is prone to sintering and shrinkage at high temperatures above 600℃, causing a sharp drop in thermal insulation efficiency. Moreover, it is only a simple superposition with the outer ceramic protective layer, lacking a synergistic thermal insulation mechanism, and the improvement in fire resistance is limited, failing to fully utilize the performance advantages of aerogel materials. At the same time, most existing aerogel fireproof cables have not simultaneously optimized waterproof structure and signal anti-interference design. In humid environments, moisture can easily penetrate into the cable core, leading to a decline in insulation performance and unstable signal transmission after long-term use, failing to simultaneously meet the multiple requirements of fire resistance, waterproofing, high mechanical strength, and stable signal transmission.

[0005] Therefore, in order to comprehensively improve the long-term fire resistance and heat insulation performance, mechanical tensile strength, waterproof and moisture-proof performance and signal transmission stability of fire-resistant cables, solve the technical problems of easy powdering, rapid high-temperature heat insulation attenuation and lack of synergistic effect of multi-layer protection of conventional aerogel cables, and meet the harsh working conditions of special scenarios such as high-rise buildings, subways, and nuclear power plants, it is currently urgent to make systematic improvements to the aerogel material system, multi-layer protection structure design and preparation method of this type of cable. Summary of the Invention

[0006] This application aims to address the technical problems in existing technologies, such as insufficient heat insulation capacity, short fire resistance time, poor mechanical strength and waterproof performance of conventional fire-resistant cables, and easy interference with signal transmission during power transmission; while existing aerogel fire-resistant cables have poor mechanical properties, are prone to pulverization after bending, and their pores are prone to collapse at high temperatures. Furthermore, the aerogel layer and the ceramicized layer lack a synergistic heat insulation mechanism, making it impossible to simultaneously achieve fire resistance, mechanical properties, waterproofing, and signal transmission stability. Therefore, this application proposes a novel fire-resistant cable with aerogel tape for signal transmission and its preparation method.

[0007] The objective of this invention is achieved through the following technical solution: a novel fire-resistant cable for signal transmission using aerogel tape, comprising at least one power conductor core, at least one signal conductor core, a filling layer filling the gaps between the conductor cores, a water channel spirally arranged in the gaps between the conductor cores, an aerogel tape layer, a ceramicized silicone tape layer, and a sheath layer sequentially covering the outer periphery of the conductor cores after cabling; the power conductor core comprises a conductor, a fire-resistant layer covering the outer periphery of the conductor, and an insulation layer extruded around the outer periphery of the fire-resistant layer; the signal conductor core comprises a signal conductor, a signal wire fire-resistant layer covering the outer periphery of the signal conductor, a signal wire insulation layer extruded around the outer periphery of the signal wire fire-resistant layer, a signal wire protective layer covering the outer periphery of the signal wire insulation layer, and a steel wire reinforcement layer braided around the outer periphery of the signal wire protective layer; the aerogel tape layer is a basalt fiber cloth-modified aerogel composite tape, employing a three-layer composite structure, with the upper and lower layers being basalt fiber cloth and the middle layer being a modified silica aerogel layer compounded with expandable graphite.

[0008] In some feasible embodiments, both the fire-resistant layer and the signal line fire-resistant layer are wrapped with multiple layers of phlogopite tape. The fire-resistant layer has two layers, each with a thickness of 0.14 mm and an overlap rate of 20%-30%. The signal line fire-resistant layer has two layers, each with a thickness of 0.14 mm and an overlap rate of 15%-25%.

[0009] In some feasible embodiments, the insulation layer is made of cross-linked polyethylene material with an insulation thickness of 0.8mm-1.0mm; the signal line insulation layer is made of fluoroplastic material with an insulation thickness of 0.4mm-0.6mm; and the signal line protective layer is made of nylon material.

[0010] In some feasible embodiments, the steel wire reinforcement layer is made of steel wire with a diameter of 0.3 mm and a braiding density of not less than 85%; the conductor is made of copper material with a purity of 99.9%; the signal line conductor is made of copper alloy material and the single wire diameter is 0.247 mm-0.648 mm.

[0011] In some feasible embodiments, the water channel adopts a spiral hollow structure with a spiral pitch of 8-12 times the outer diameter of the cable; the filling layer adopts flame-retardant filling rope, which is densely filled in the gap of the cable core to ensure the roundness of the cable core.

[0012] In some feasible embodiments, the aerogel tape layer has one wrapping layer with a tape thickness of 0.7mm-0.8mm and a wrapping overlap rate of 20%-30%; the ceramicized silicone tape layer has two wrapping layers with a single layer thickness of 0.25mm and a wrapping overlap rate of 15%-25%.

[0013] In some feasible embodiments, the sheath layer is made of low-smoke halogen-free polyolefin material, and the thickness of the sheath layer is 1.8mm-2.2mm.

[0014] In some feasible embodiments, the modified silica aerogel layer is composed of the following components by weight: 75-85 parts of silane coupling agent modified silica aerogel powder, 15-25 parts of expandable graphite micro powder, and 5-10 parts of silicone rubber binder; the expandable graphite micro powder has a particle size of 200-300 mesh and an expansion ratio of not less than 200 mL / g.

[0015] To address the technical problems raised in this application, this application also provides a method for preparing a novel fire-resistant cable for signal transmission using aerogel tape, comprising the following steps: Step S1. Preparation of power conductor core: The copper conductor is fed into a horizontal wrapping machine, and a fire-resistant layer is prepared by double-layer overlapping wrapping with phlogopite tape. The overlap rate of each wrapping layer is controlled at 20%-30%, the wrapping tension at 8N-12N, and the wrapping speed at 250rpm-350rpm. The conductor covered with the fire-resistant layer is then transferred to a single-screw extruder to extrude a cross-linked polyethylene insulation layer. After extrusion, it is sent to a warm water cross-linking tank for cross-linking at a temperature of 70℃-85℃ for 4h-6h. Then, it is water-cooled at 20℃-30℃ for shaping. The extrusion temperature is controlled at 160℃-165℃ in zone 1, 170℃-175℃ in zone 2, 180℃-185℃ in zone 3, and 175℃-180℃ at the die head. The extrusion thickness is 0.8mm-1.0mm. After extrusion, it is water-cooled at 20℃-30℃ for shaping to obtain the power conductor core. Step S2. Signal wire core preparation: Copper alloy monofilaments are transferred to a wire bundling machine and twisted into signal wire conductors, with a wire pitch ratio of 14-16 times; then, the signal wire is wrapped with a fire-resistant layer by a horizontal wrapping machine, a fluoroplastic signal wire insulation layer by a single-screw extruder, and a signal wire protective layer by a nylon extruder; finally, the signal wire with the protective layer is transferred to a high-speed braiding machine to braid a steel wire reinforcement layer with 0.3mm steel wire, controlling the braiding density ≥85% and the braiding speed 150rpm-200rpm to obtain the signal wire core; Step S3. Cable making and water channel layout: Transfer the power core and signal core into the cage-type cable making machine for stranding into a cable. The stranding pitch ratio is 10-12 times and the cable making speed is 80rpm-120rpm. During the cable making process, hollow water channels are spirally laid in the gaps between the cable cores and filled with flame-retardant filler rope to ensure that the cable core is round and dense. Step S4. Composite insulation layer wrapping: Transfer the cable core after cabling into a horizontal wrapping machine. First, wrap an aerogel tape layer, controlling the wrapping overlap rate to 20%-30%, the wrapping tension to 10N-15N, and the wrapping speed to 150rpm-200rpm. Then, wrap two layers of ceramicized silicone tape around the outer periphery of the aerogel tape layer, controlling the overlap rate of each layer to 15%-25%, the wrapping tension to 12N-18N, and the wrapping speed to 180rpm-220rpm. Step S5. Sheath Extrusion and Finished Product Inspection: Transfer the wrapped cable into a single-screw extruder to extrude a low-smoke halogen-free polyolefin sheath layer. Control the extrusion temperature: Zone 1 130℃-135℃, Zone 2 140℃-145℃, Zone 3 150℃-155℃, and die head 145℃-150℃. The extrusion thickness is 1.8mm-2.2mm. After extrusion, water cooling and shaping are performed, followed by appearance inspection and performance testing. Once qualified, the finished cable is obtained.

[0016] Compared with the prior art, this application has the following beneficial effects: 1. Three-level synergistic fire protection and leapfrog improvement in thermal insulation performance: The cable provided in this application constructs a three-level synergistic fire protection system through basalt fiber cloth-modified aerogel composite tape, ceramicized silicone tape and spiral water channel. With the help of the evaporative cooling effect of the spiral water channel, the synergistic effect of the multi-layer structure is achieved, resulting in longer fire resistance time and higher thermal insulation efficiency, which is far superior to the linear superposition effect of each layer acting alone. It solves the technical problems of easy collapse of high temperature pores and rapid thermal insulation decay of conventional aerogel cables, and can meet the long-term line integrity requirements in extreme scenarios.

[0017] 2. Highly stable aerogel composite structure with significantly extended service life: Basalt fiber cloth is used as the reinforcing substrate of the aerogel tape, and it is cured with silicone rubber adhesive, which greatly improves the bending resistance and structural stability of the aerogel tape. The heat insulation performance retention rate after bending is over 90%, effectively avoiding the problem of aerogel powdering and falling off. It is suitable for complex laying scenarios and the long-term service reliability is significantly improved.

[0018] 3. Multifunctional integrated design with comprehensive and balanced performance: The steel wire braided layer on the outer layer of the signal cable simultaneously enhances tensile strength and provides electromagnetic shielding. The spiral water channel serves both daily water drainage and moisture prevention as well as fire cooling, enabling the cable to simultaneously possess high mechanical strength, excellent waterproof performance, and stable signal transmission capability. This integrated structure eliminates the need to lay power cables and signal cables separately, reducing construction difficulty and cost.

[0019] 4. The overall manufacturing process is based on existing mature cable production equipment, the process is controllable, and it has strong industrial applicability. Mass production can be achieved by optimizing the wrapping and extrusion process parameters. No new special equipment is required. The process stability and product consistency are good, which facilitates large-scale promotion and application. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cross-sectional structure of a novel fireproof cable for signal transmission using aerogel tape, as described in this application.

[0021] Explanation of markings in the diagram: 1-Conductor, 2-Fire-resistant layer, 3-Insulation layer, 4-Signal line conductor, 5-Signal line fire-resistant layer, 6-Signal line insulation layer, 7-Signal line protective layer, 8-Steel wire reinforcement layer, 9-Water channel, 10-Filling layer, 11-Aerogel tape layer, 12-Ceramicized silicone tape layer, 13-Sheath layer; Figure 2 This is a process flow diagram of the preparation method of a novel fireproof cable for signal transmission using aerogel tape according to this application. Detailed Implementation

[0022] Combination Figures 1-2 Examples 1-3 and Comparative Examples 1-5 further illustrate the technical solutions proposed in this application.

[0023] Specifically, a novel fire-resistant cable for signal transmission using aerogel tape includes at least one power conductor, at least one signal conductor, a filling layer 10 filling the gaps between the conductors, a water channel 9 spirally arranged in the gaps between the conductors, an aerogel tape layer 11, a ceramicized silicone tape layer 12, and a sheath layer 13 sequentially covering the outer periphery of the conductors after cabling. The power conductor includes a conductor 1, a fire-resistant layer 2 covering the outer periphery of the conductor 1, and an insulation layer 3 extruded around the outer periphery of the fire-resistant layer 2. The signal conductor includes a signal... The signal conductor 4, the signal wire fire-resistant layer 5 covering the outer periphery of the signal wire conductor 4, the signal wire insulation layer 6 extruded around the outer periphery of the signal wire fire-resistant layer 5, the signal wire protective layer 7 covering the outer periphery of the signal wire insulation layer 6, and the steel wire reinforcement layer 8 woven around the outer periphery of the signal wire protective layer 7; the aerogel tape layer 11 is a basalt fiber cloth-modified aerogel composite tape, which adopts a three-layer composite structure, with the upper and lower layers being basalt fiber cloth and the middle layer being a modified silica aerogel layer compounded with expandable graphite.

[0024] Preferably, the fire-resistant layer 2 and the signal line fire-resistant layer 5 are both wrapped with multiple layers of phlogopite tape; the insulation layer 3 is made of cross-linked polyethylene (XLPE); the signal line insulation layer 6 is made of fluoroplastic; the signal line protective layer 7 is made of nylon; the steel wire reinforcement layer 8 is woven from steel wire with a diameter of 0.3 mm; the water channel 9 has a spiral hollow structure; the filling layer 10 is made of flame-retardant filling rope; the ceramicized silicone tape layer 12 is made of ceramicized silicone tape; and the sheath layer 13 is made of low-smoke halogen-free polyolefin (LSZH) material. Example 1

[0025] [1] Preparation of modified aerogel composite tape: Weigh each raw material accurately according to the composition table shown in Table 1. Add the silane coupling agent KH-550 modified silica aerogel powder and expandable graphite micro powder to a high-speed mixer and mix at 800 rpm for 15 min until uniform. Add room temperature vulcanized methyl silicone rubber binder and continue mixing for 10 min to obtain aerogel composite slurry. Coat the slurry evenly between two layers of basalt fiber cloth, roll-press it, cure it at 90℃ for 3 h, and cut it into composite tape with a width of 50 mm and a thickness of 0.75 mm to obtain aerogel tape raw material.

[0026] [2] Preparation of power conductor core: Select a copper conductor with a diameter of 1.5 mm and a purity of 99.9%, and feed it into a horizontal wrapping machine. Use a 0.14 mm thick mica tape to wrap the fire-resistant layer in double layers. Control the overlap rate of each wrapping layer to 25%, the wrapping tension to 10 N, and the wrapping speed to 300 rpm. Then feed the conductor covered with the fire-resistant layer into a φ65 single screw extruder to extrude a cross-linked polyethylene insulation layer. Control the extrusion temperature to 162℃ in zone 1, 172℃ in zone 2, 182℃ in zone 3, and 178℃ at the die head. The extrusion thickness is 0.9 mm. After extrusion, it is water-cooled at 25℃ to shape and obtain the power conductor core.

[0027] [3] Signal wire core preparation: Seven copper alloy monofilaments with a diameter of 0.3 mm were selected and fed into a wire bundling machine to be twisted into signal wire conductors with a wire pitch ratio of 15. Then, a 0.14 mm thick mica tape signal wire fire-resistant layer was wrapped around it using the same process as power wire cores, with an overlap rate of 20%. Subsequently, it was fed into a single screw extruder to extrude a fluoroplastic signal wire insulation layer at an extrusion speed of 21 m / min and an extrusion thickness of 0.5 mm. Then, a 0.15 mm thick nylon signal wire protective layer was extruded through a nylon extruder. Finally, the signal wire covered with the protective layer was fed into a high-speed braiding machine to braid a steel wire reinforcement layer with 0.3 mm high-strength steel wire, with a braiding density of 88% and a braiding speed of 180 rpm, to obtain the signal wire core.

[0028] [4] Cable making and water channel layout: Three power cores and two signal cores are fed into a cage-type cable making machine for stranding into a cable. The stranding pitch ratio is 11 and the cable making speed is 100 rpm. Simultaneously, a sealed hollow water channel made of PP material is spirally laid in the gap between the cable cores. The water channel has an inner diameter of 2 mm and a wall thickness of 0.5 mm. It is filled with deionized water and the two ends are heat-sealed. The spiral pitch is 10 times the outer diameter of the cable and is filled with flame-retardant polypropylene filler rope to ensure that the cable core is round and dense.

[0029] [5] Composite insulation layer wrapping: The cable core after cabling is sent into a horizontal wrapping machine. First, wrap the aerogel tape layer prepared in step [1], controlling the wrapping overlap rate of 25%, the wrapping tension of 12N, and the wrapping speed of 180rpm. Then, wrap two layers of 0.25mm thick ceramicized silicone tape around the outer periphery of the aerogel tape layer, controlling the overlap rate of each layer of 20%, the wrapping tension of 15N, and the wrapping speed of 200rpm.

[0030] [6] Sheath extrusion and finished product inspection: The wrapped cable is fed into a φ90 single screw extruder to extrude a low-smoke halogen-free polyolefin sheath layer. The extrusion temperature is controlled at 132℃ in zone 1, 142℃ in zone 2, 152℃ in zone 3, and 148℃ at the die head. The extrusion thickness is 2.0mm. After extrusion, the cable is water-cooled at 25℃ for shaping. Then, the appearance inspection and performance test are carried out. After passing the test, the cable is rolled and packaged to obtain the finished cable. Example 2

[0031] Modify the composition ratio of the modified silica aerogel layer according to the composition table shown in Table 1, and keep the other process and structural parameters consistent with Example 1. Example 3

[0032] Modify the composition ratio of the modified silica aerogel layer according to the composition table shown in Table 1, and keep the other process and structural parameters consistent with Example 1.

[0033] Comparative Example 1 The aerogel tape layer was removed, and only two layers of ceramicized silicone tape were retained as heat insulation and fireproof layers. The remaining processes and structural parameters remained the same as in Example 1.

[0034] Comparative Example 2 The aerogel tape layer is made of ordinary glass fiber cloth-pure silica aerogel composite tape, without any expandable graphite components, and the remaining process and structural parameters are consistent with those in Example 1.

[0035] Comparative Example 3 The aerogel layer uses ordinary glass fiber cloth instead of basalt fiber cloth. The composition of the aerogel layer is the same as in Example 2, and the remaining process and structural parameters are the same as in Example 1.

[0036] Comparative Example 4 The ceramicized silicone tape layer was removed, and only the aerogel tape layer was retained as a heat insulation and fireproof layer. The remaining process and structural parameters remained the same as in Example 2.

[0037] Comparative Example 5 The spiral water channel structure was removed, and all gaps between the cable cores were filled with flame-retardant filler rope. The remaining processes and structural parameters remained the same as in Example 2.

[0038] Table 1. Components of the modified silica aerogel layer (parts by weight) As shown in Table 2, the finished cables prepared in Examples 1-3 and Comparative Examples 1-5 were subjected to performance tests.

[0039] Table 2 Test Content

[0040] The test results are shown in Table 3 below.

[0041] Table 3 Performance Test Results As shown in Table 3, the test results indicate that in Examples 1-3, by compounding modified silica aerogel with expandable graphite in a specific ratio of 75-85:15-25, combined with a basalt fiber cloth composite structure, and then working synergistically with the outer ceramicized silicone tape and spiral water channels, the overall performance of the cable is significantly improved. All indicators are far superior to those of the other ratios, and there is a clear synergistic effect.

[0042] On the one hand, the expandable graphite compounded in the modified aerogel layer expands rapidly under high temperature conditions (above 200℃). The expanded worm-like graphite fills the macroscopic gaps between the aerogel powders, forming a continuous carbonaceous thermal insulation layer that blocks heat convection and radiation, while simultaneously inhibiting the high-temperature shrinkage and deformation of the aerogel layer. This not only blocks the heat convection channels within the pores, reducing gas heat transfer efficiency, but also forms a continuous carbonaceous thermal insulation skeleton, inhibiting the sintering collapse of the aerogel nanopores above 600℃, allowing the aerogel layer to maintain a stable thermal insulation structure at high temperatures. Compared with Comparative Example 2, which uses pure aerogel, the fire resistance time of Example 2 increased from 92 min to 142 min, an increase of 54.3%, and the temperature rise of the cable core decreased from 118℃ to 61℃ after 30 min, a reduction of 48.3%. The combination of the two materials simultaneously achieves pore sealing and structural support, resulting in a significant improvement in thermal insulation performance, demonstrating the synergistic effect of the material system.

[0043] On the other hand, basalt fiber cloth replaces ordinary glass fiber cloth as the upper and lower reinforcing layers of the aerogel tape. Thanks to the higher high-temperature resistance and mechanical strength of basalt fiber, the bending resistance and structural stability of the composite tape are significantly improved. Compared with Comparative Example 3, which uses glass fiber substrate, the thermal insulation performance retention rate after 100 bends in Example 2 increased from 72.6% to 93.5%, effectively solving the technical problems of easy pulverization and significant attenuation of thermal insulation performance of conventional aerogel tapes after bending. This allows the cable to adapt to complex bending installation scenarios, significantly improving its long-term service stability.

[0044] More importantly, the aerogel tape layer and the ceramicized silicone tape layer form a layered synergistic protection system of "external barrier and internal heat insulation": the outer ceramicized silicone tape rapidly forms a hard ceramicized shell in the flame, blocking the intrusion of open flame and oxygen, while resisting external mechanical impact and reducing the inward transfer of heat radiation and heat convection; the inner modified aerogel tape slows down the heat conduction rate through the dual structure of nanopores and expanded graphite carbon layers. With the two combined, the cable core temperature rise after 30 minutes is only 61℃, far lower than Comparative Example 1 (165℃) containing only the ceramicized layer and Comparative Example 4 (143℃) containing only the aerogel layer. The heat insulation effect is significantly better than that of single-layer protection, demonstrating the synergistic effect of the multi-layer structure.

[0045] Furthermore, the sealed spiral water channel design achieves dual functions of moisture-proofing and fireproofing: Under normal operating conditions, the sealed hollow structure can prevent external moisture from penetrating into the cable core, balancing the internal humidity of the cable core. Compared with the waterless channel in Comparative Example 5, the insulation resistance retention rate after 72 hours of immersion in water increased from 82.3% to 97.1%, significantly improving moisture-proof performance. Under fire conditions, the deionized water encapsulated in the channel evaporates upon heating, absorbing a large amount of latent heat and slowing down the initial temperature rise rate of the cable core. Combined with the heat insulation effect of aerogel, this further extends the fire resistance time. The steel wire reinforcement layer on the outer layer of the signal line not only stabilizes the overall tensile strength of the cable above 180MPa, but also forms an electromagnetic shielding layer, effectively blocking electromagnetic interference from the power line to the signal line, keeping the signal error rate below 0.015% under fire conditions, achieving the dual functions of mechanical reinforcement and signal shielding.

[0046] After removing the aerogel tape layer, Comparative Example 1 relies solely on the ceramicized silicone tape and mica fire-resistant layer, lacking an efficient heat insulation structure. The heat from the flame is rapidly transferred to the cable core, with a fire resistance time of only 68 minutes at 950°C. The cable core temperature rises to 165°C in 30 minutes, far from meeting the long-term fire resistance requirements in extreme scenarios. At the same time, the signal transmission lacks shielding protection, and the bit error rate increases to 0.035% under fire conditions. The overall performance is significantly different from that of the Example Group.

[0047] Comparative Example 2 uses pure silica aerogel fiberglass tape, without any expandable graphite composite. At high temperatures, the aerogel pores are prone to sintering and collapse, resulting in a sharp drop in thermal insulation efficiency. The fire resistance time is only 92 minutes, and the cable core temperature rises to 118°C in 30 minutes. Furthermore, the mechanical properties of ordinary fiberglass substrates are poor, and the aerogel powders severely after bending. The thermal insulation performance retention rate is only 68.4%, resulting in insufficient long-term service reliability. The overall performance is far inferior to that of the Example Group.

[0048] Comparative Example 3 uses ordinary fiberglass substrate combined with composite aerogel. The high temperature resistance and mechanical strength of fiberglass are weaker than those of basalt fiber. After bending, the fiber is easy to break and more aerogel falls off, resulting in a heat insulation retention rate of only 72.6%. At the same time, fiberglass is easy to melt and soften at high temperatures, and cannot provide effective structural support for the aerogel layer. Its high temperature heat insulation performance is inferior to that of basalt fiber substrate, and its fire resistance time and cable core temperature rise are significantly worse than those of the Example Group.

[0049] Comparative Example 4 removed the ceramicized silicone tape layer, leaving only the aerogel tape for insulation. The outer layer lacked a hard ceramicized shell to block open flames and oxygen. The flame directly acted on the surface of the aerogel tape, causing the aerogel layer to heat up rapidly and the pores to collapse at an accelerated rate. The fire resistance time was only 76 minutes, and the insulation effect was greatly reduced. This proves that the synergistic cooperation between the ceramicized layer and the aerogel layer is a necessary condition for achieving high fire resistance.

[0050] Comparative Example 5, without the spiral water channel, shows that the moisture seeping into the cable core cannot be effectively blocked, and the insulation performance drops significantly after long-term immersion, with the insulation resistance retention rate only 82.3%. At the same time, the lack of water evaporation for cooling during a fire accelerates the initial temperature rise of the cable core, and the fire resistance time drops from 142 minutes to 112 minutes, proving that the water channel plays an irreplaceable synergistic role in both moisture prevention and fire prevention.

[0051] In summary, this application provides a novel fire-resistant cable for signal transmission using aerogel tape and its preparation method. The cable constructs a three-tiered synergistic fire-resistant system through basalt fiber cloth-modified aerogel composite tape, ceramicized silicone tape, and spiral water channels, complemented by a signal core structure with a steel wire reinforcement layer. The modified aerogel layer is compounded with a specific proportion of expandable graphite micropowder, utilizing the synergistic effect of aerogel nanopore insulation, high-temperature expansion sealing of expandable graphite, and ceramicized shell barrier to significantly improve heat insulation efficiency and fire resistance time at high temperatures. Simultaneously, the spiral water channels provide both daily water and moisture protection and fire evaporation cooling. The steel wire reinforcement layer of the signal line simultaneously achieves tensile strength enhancement and electromagnetic shielding, enabling the cable to possess excellent fire resistance, mechanical tensile strength, waterproof and moisture-proof performance, and stable signal transmission capability. It is stably applicable to harsh conditions such as high-rise buildings and subways, and has the advantages of controllable manufacturing process, stable performance, and ease of promotion and implementation.

[0052] The embodiments provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A novel fire-resistant cable for signal transmission using aerogel tape, characterized in that, It includes at least one power core, at least one signal core, a filling layer filling the gap between the cable cores, a water channel spirally arranged in the gap between the cable cores, an aerogel tape layer, a ceramicized silicone tape layer, and a sheath layer that are sequentially wrapped around the outer periphery of the cable core after cable formation. The power conductor core includes a conductor, a fire-resistant layer covering the outer periphery of the conductor, and an insulating layer extruded around the outer periphery of the fire-resistant layer; The signal wire core includes a signal wire conductor, a signal wire fire-resistant layer covering the outer periphery of the signal wire conductor, a signal wire insulation layer extruded around the outer periphery of the signal wire fire-resistant layer, a signal wire protective layer covering the outer periphery of the signal wire insulation layer, and a steel wire reinforcement layer braided around the outer periphery of the signal wire protective layer. The aerogel tape layer is a basalt fiber cloth-modified aerogel composite tape. The aerogel tape layer has a three-layer composite structure, with the upper and lower layers being basalt fiber cloth and the middle layer being a modified silica aerogel layer with expanded graphite.

2. The novel fireproof cable for signal transmission using aerogel tape according to claim 1, characterized in that, Both the fire-resistant layer and the fire-resistant layer of the signal line are wrapped with multiple layers of phlogopite tape. The fire-resistant layer has two layers, each with a thickness of 0.14 mm and an overlap rate of 20%-30%. The fire-resistant layer of the signal line has two layers, each with a thickness of 0.14 mm and an overlap rate of 15%-25%.

3. The novel fireproof cable for signal transmission using aerogel tape according to claim 1, characterized in that, The insulation layer is made of cross-linked polyethylene material with an insulation thickness of 0.8mm-1.0mm; the signal line insulation layer is made of fluoroplastic material with an insulation thickness of 0.4mm-0.6mm; and the signal line protective layer is made of nylon material.

4. The novel fireproof cable for signal transmission using aerogel tape according to claim 1, characterized in that, The steel wire reinforcement layer is made of steel wire with a diameter of 0.3 mm and a braiding density of not less than 85%; the conductor is made of copper material with a purity of 99.9%; the signal line conductor is made of copper alloy material and the single wire diameter is 0.247 mm-0.648 mm.

5. The novel fireproof cable for signal transmission using aerogel tape according to claim 1, characterized in that, The water channel adopts a spiral hollow structure with a spiral pitch of 8-12 times the outer diameter of the cable; the filling layer uses flame-retardant filling rope, which is densely filled into the gaps between the cable cores to ensure the roundness of the cable cores.

6. The novel fireproof cable for signal transmission using aerogel tape according to claim 1, characterized in that, The aerogel tape layer has one wrapping layer with a thickness of 0.7mm-0.8mm and a wrapping overlap rate of 20%-30%; the ceramicized silicone tape layer has two wrapping layers with a single layer thickness of 0.25mm and a wrapping overlap rate of 15%-25%.

7. The novel fireproof cable for signal transmission using aerogel tape according to claim 1, characterized in that, The sheath layer is made of low-smoke halogen-free polyolefin material, and the thickness of the sheath layer is 1.8mm-2.2mm.

8. The novel fireproof cable for signal transmission using aerogel tape according to claim 1, characterized in that, By weight, the modified silica aerogel layer is composed of the following components: 75-85 parts of silane coupling agent modified silica aerogel powder, 15-25 parts of expandable graphite micro powder, and 5-10 parts of silicone rubber binder; the expandable graphite micro powder has a particle size of 200-300 mesh and an expansion ratio of not less than 200 mL / g.

9. A method for preparing a novel fire-resistant cable for signal transmission using aerogel tape according to any one of claims 1-8, characterized in that, Includes the following steps: Step S1. Preparation of power conductor core: The copper conductor is fed into a horizontal wrapping machine, and a fire-resistant layer is prepared by double-layer overlapping wrapping with phlogopite tape. The overlap rate of each wrapping layer is controlled at 20%-30%, the wrapping tension is 8N-12N, and the wrapping speed is 250rpm-350rpm. Then, the conductor covered with the fire-resistant layer is transferred to a single-screw extruder to extrude a cross-linked polyethylene insulation layer. The extrusion temperature is controlled at 160℃-165℃ in zone 1, 170℃-175℃ in zone 2, 180℃-185℃ in zone 3, and 175℃-180℃ at the die head. The extrusion thickness is 0.8mm-1.0mm. After extrusion, the conductor is water-cooled at 20℃-30℃ for shaping to obtain the power conductor core. Step S2. Signal wire core preparation: Copper alloy monofilaments are transferred to a wire bundling machine and twisted into signal wire conductors, with a wire pitch ratio of 14-16 times; then, the signal wire is wrapped with a fire-resistant layer by a horizontal wrapping machine, a fluoroplastic signal wire insulation layer by a single-screw extruder, and a signal wire protective layer by a nylon extruder; finally, the signal wire with the protective layer is transferred to a high-speed braiding machine to braid a steel wire reinforcement layer with 0.3mm steel wire, controlling the braiding density ≥85% and the braiding speed 150rpm-200rpm to obtain the signal wire core; Step S3. Cable making and water channel layout: Transfer the power core and signal core into the cage-type cable making machine for stranding into a cable. The stranding pitch ratio is 10-12 times and the cable making speed is 80rpm-120rpm. During the cable making process, hollow water channels are spirally laid in the gaps between the cable cores and filled with flame-retardant filler rope to ensure that the cable core is round and dense. Step S4. Composite insulation layer wrapping: Transfer the cable core after cabling into a horizontal wrapping machine. First, wrap an aerogel tape layer, controlling the wrapping overlap rate at 20%-30%, the wrapping tension at 10N-15N, and the wrapping speed at 150rpm-200rpm. Then, wrap two layers of ceramicized silicone tape around the outer periphery of the aerogel tape layer, controlling the overlap rate of each layer at 15%-25%, the wrapping tension at 12N-18N, and the wrapping speed at 180rpm-220rpm. Step S5. Sheath Extrusion and Finished Product Inspection: Transfer the wrapped cable into a single-screw extruder to extrude a low-smoke halogen-free polyolefin sheath layer. Control the extrusion temperature: Zone 1 130℃-135℃, Zone 2 140℃-145℃, Zone 3 150℃-155℃, and die head 145℃-150℃. The extrusion thickness is 1.8mm-2.2mm. After extrusion, water cooling and shaping are performed, followed by appearance inspection and performance testing. Once qualified, the finished cable is obtained.

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